Funds are requested for the acquisition of a high sensitivity, rapid throughput protein sequencer for the sequence analysis of proteins and peptides. The instrument will be housed in the Center for the Analysis and Synthesis of Macromolecules (CASM) in the Department of Physiology & Biophysics at Stony Brook, and operated as a shared facility overseen by the School of Medicine and the Center for Biotechnology. Projects will be conducted by eight major faculty, and as many as twenty other faculty users from the departments of Physiology & Biophysics, Medicine, Biochemistry, Chemistry, Oral Biology & Pathology, and other departments whose research requires the sequence analysis of proteins and peptides. Samples to be analyzed include covalent protein-ligand complexes, glycopeptides, phosphopeptides, photoaffinity modified peptides, and peptides from enzymatic digests of posttranslationally-modified proteins.